The present invention relates to an automobile body and frame straightening apparatus for straightening and aligning automobile frames and bodies, in particular to an automobile body and frame straightening apparatus having a hydraulically operated body gripping supports to rigidly hold the automobile body and frame in a fixed position during the straightening and aligning thereof.
Automobile body and frame straightening apparatus have been known for decades, dating back to the very earliest apparatus which required skilled personnel to haul heavy and sometimes awkward equipment from one side of the automobile to the other. Usually the apparatus comprised a rigid stationary ramp frame, either sunk into the floor or ground, or supported above the ground by a base. The automobile was secured to the ramp frame by chains wrapped around any available part such as the axles, bumpers or, if possible, the frame. In turn, a frame puller was attached to the section of the automobile body frame to which a force was applied. The time necessary to set up and straighten an automobile often required two men working together a day or more to complete. Today the same repair can be completed in a third of the time using modern equipment.
Previous body securing devices for holding an automobile against movement included specially constructed posts or trestles bolted directly to the automobile frame. In straightening and aligning to today's modern automobile with unitized construction, it has become necessary for automobile manufacturers to provide specifications on load bearing points on the frame which can be utilized for attaching body securing devices. It is required of all automobile manufacturers to provide for each model and particular body type the number and locations of load bearing points suitable for supporting purposes, particularly on the underside of the bottom plate from which measurements are made to determine the deformations of the body. This replacement is to ensure that the automobile, after straightening and alignment, has regained its original shape corresponding to the drawings, so as to fulfill all traffic safety requirements.
As a result of the requirement to supply detailed information on load bearing points and the number of different types of load bearing points, manufacturers of automobile frame straightening equipment manufacture and market sets of body securing devices for each automobile make, type and model. The economically profitable period for most alignment operations is about 3 to 5 years; therefore, even the larger alignment work shops are limited in the number of opportunities to use the complete line of body frame securing devices. Thus it is obvious that the investment in view of the short useful period makes it impossible for even the best equipped shop to purchase all of the body frame securing devices for each type of automobile. To overcome the problem of carrying a complete line of body frame securing devices, universally adaptable securing devices with clamping jaws which attach to the pinch weld rim along the underside of the automobile, i.e., the so-called rocker panels, was developed. The pinch weld rims have increased strength, because of the need to provide torsional stiffness and load bearing capabilities of the unitized body construction. The pinch weld rims, therefore, can be advantageously used for attachment purposes.
A common difficulty with the previously mentioned securing devices is that several man hours are required to position the securing devices in proper alignment with the automobile frame and the place on the ramp or other stationary hold down apparatus to rigidly support the automobile. At the same time the securing device must be positioned on the automobile at a location which will not interfere with the body frame straightening and alignment operation. The old practice of a chain wrapped around the axle, or frame, or body parts of the automobile and anchored to the ramp is limited in regard to modern alignment operations since quite often the pulling force is applied in a direction not firmly supported. Other prior securing devices which do provide a greater range of automobile support during the straightening operation are often complex to operate.
One of the more recent attempts at a vehicle body and frame apparatus and vehicle body frame securing clamps is shown in Borup, U.S. Pat. No. 4,023,394. The apparatus includes a pair of transverse beams with securing clamps for clamping to the underside of the vehicle body so as to permit these beams to be clamped in horizontal parallel spaced relationship to each other and transversely to the vehicle's longitudinal axis. Each of the beams has supporting wheels to permit raising and moving the vehicle for inserting under the beams a rigid rectangular frame of similar length as the vehicle and lesser width than the length of each of the beams. Clamping bolts join the transverse beams to the rigid frame to provide a rigid structure which in turn supports force-applying apparatus. The Borup apparatus includes slots in the transverse beams and rigid frame for aligning the securing clamps with the vehicle body weld rims and aligning the transverse beams with the rigid frame. This apparatus has certain advantages over prior alignment apparatus, but the set-up time and manual labor required detract from broad acceptance.
U.S. Pat. No. 4,070,899, issued to Venalainen shows an automobile body and frame straightener which secures the automobile against movement during the straightening operation. There is provided a hydraulic assembly with a pivotal lift for raising the automobile to working height. A plurality of clamping devices mounted on transverse beams are manually adjusted to grip the weld rims of the automobile to support it. The only adjustment is along the transverse beams, therefore there is a problem with aligning the automobile frame in relation to the clamping devices if a section of the twisted frame is near a weld rim where the clamping device is located.
Tiedown hooks and chains are shown in U.S. Pat. No. 3,630,066--Chisum where the hooks fasten to the frame and the chain fastens to the ramp. Chisum also discloses body frame pullers pivotally mounted for working on the front and sides of the automobile.